Biomechanist Katy Bowman introduced me to the concept of casting. When you cast something, you immobilize it and its ingredients adapt to the shape of the cast. It happens in metals, clays, and body tissues. If you’ve ever broken a bone and worn a cast, you know that when you finally remove the cast, your tissues – bone, muscles, tendons, ligaments, fascia, even skin – have adapted to the position they have been held or casted in. We cast our bodies in many ways and with many apparati.
Take feet, for example. Most human feet are casted into the shapes of their shoes for many hours a day and have been that way for almost as many years as their operators have been alive. If your shoes have a tight toe box, are thick and rigidly soled, and have positive heels (any amount of heel elevation relative to the toe) then you have been casting your feet into a tight, weak, motor and sensory deprived mess. Maybe its what brought you to this blog.
Another way we cast our feet, which is particularly problematic for plantar fasciitis (PF), is by keeping them in plantar flexion aka “pointer” flexion, pointing our toes like a ballerina, when we sleep. This position is known to aggravate PF. Try this. Get in bed, lie on your back, pull on your heavy winter covers and notice what position your feet are in. They will be pointing. Now, pull the covers off of your feet and notice how they come into a more neutral position, not quite dorsiflexed (aka flexing your foot or ankle – opposite of pointing), but less plantar flexed. Podiatrists will sometimes prescribe an orthotic called a night splint that you wear to keep your foot in dorsiflexion. But a less extreme and more comfortable alternative that you might try if night splints are not for you is simply donning soft, warm socks (sadly, also a cast, but less problematic than plantar flexing) and sleep with your feet out of the covers.
If you turn over onto your belly, regardless of whether your feet are covered, your feet will automatically be in plantar flexion – again, bad for PF. If you are a belly sleeper and have PF, try to cultivate the habit of sleeping on your back or side. Start out your sleep this way and move onto your back/side whenever you naturally wake up during the night.